As is known, musk is rare and expensive. Perfumes having a musky scent which are more readily available are therefore sought-after components for the perfume industry. 15-Pentadecanolide of the formula ##STR2## is a constituent of angelica root oil and has a delicate musky scent and the ability to act as a fixative. There have therefore already been intensive efforts to prepare such macrocyclic lactones. The most important syntheses at present start from 13-oxabicyclo [10.4.0]hexadec-1(12)ene, which can be prepared, for example, by free-radical addition of allyl alcohol onto cyclododecanone and acid-catalysed dehydration of the resulting 2-(.gamma.-hydroxypropyl)-cyclododecanone (DE-B 21 36 496)U.S. Pat. No. 3,856,815.
In another process, hydrogen peroxide or alkyl peroxide is added onto 13-oxabicyclo [10.4.0]hexadec-1(12)ene in the presence of sulphuric acid. Thermal or UV-initiated cleavage of the resulting 12-hydroperoxy-13-oxabicyclo[10.4.0]hexadecane (III) gives 15-pentadecanolide (I) and 15-pentadecenolides, which can be hydrogenated to give I (DE-B 2 026 056).
According to Russian Inventor's Certificate 1 133 274, 12-oxo-15-pentadecanolide is reduced in the presence of Raney nickel to give 12-hydroxy-15-pentadecanolide, which is then dehydrated, for example in the presence of phosphoric acid, to give the corresponding 15-pentadec-11- and -12-enolides, and these products are then hydrogenated in the presence of a nickel catalyst to give I.
Surprisingly, it has been found that tetradecenolides whose C.dbd.C double bonds are in the 11- or 12-position and the corresponding saturated compounds have valuable organoleptic properties.